Your body 'gained' that strength without the extra mass. So it doesn't need more muscle, unless you force it beyond that and try to get even stronger.

As in - What you can lift is still limited to the mechanical strength of your muscles, otherwise you wouldn't have been able to lift the weight regardless of how strong your neural pathways are. Maybe you just weren't lifting what your muscles were already capable of - and now you can.

If you have already gained a lot of neural strength while cutting, your body might be ready for a deload soon, if you can't keep up the progress with the extra cals it will go to fat

Just things to consider

No doubt you will appear to have gained mass once the glygogen refills a bit and your muscles get back to normal. Might put a couple of kg of water/ glygogen / food/ poop back on. But if it happens too fast you don't know where it stops